PPPL is first among more than 750 companies, colleges and universities, hospitals and municipalities enrolled in the DEP's Environmental Stewardship program, in which facilities voluntarily monitor themselves to improve their sustainability programs. The program rates facilities in categories including reducing greenhouse gas emissions, green building certification and green purchasing. PPPL has actively improved its performance in each of those areas.

"The Princeton Plasma Physics Laboratory, long a leader in the area of fusion energy research, is also a leader in the area of being a good steward of the environment," DEP Commissioner Bob Martin said. "I commend their efforts at making sound environmental practices that benefit their staff, their community and their state an integral part of the facility's daily operations."

In a ceremony at PPPL on May 20, DEP Assistant Commissioner Wolfgang Skacel said the lab's achievement in meeting the standards is "unique."

"We have a program that has 21 different categories and nobody has reached 21, but only one facility has reached 20 out of the 21 and that's PPPL," he said. "Kudos to all of you."

Skacel presented PPPL Director Stewart Prager with a certificate recognizing the lab as the leading facility for environmental stewardship. Prager thanked Skacel for the recognition.

"It means a lot," said Prager, who is also a professor of astrophysical sciences at Princeton. "We're internally motivated to do this but somehow an outside pat on the back makes a big difference."

Adam Cohen, PPPL'S deputy director for operations, said the lab's efforts extended throughout the facility and to all employees.

"We are committed to protecting the environment; our mission, for example, to enable fusion energy — a clean, green, safe and nearly inexhaustible source of power — illustrates that commitment," Cohen said. "We have worked hard over many years to reduce our energy use and carbon emissions, convert our vehicles to more environmentally friendly fuels, compost our waste, and in general, implement a broad-based sustainability program. This recognition by New Jersey is a great honor and a tribute to our commitment to the environment."

The laboratory, which is part of the national laboratory system funded by the U.S. Department of Energy (DOE), received the DOE's 2012 Sustainability award for cutting its carbon footprint nearly in half in three years. The laboratory's main office building is LEED Gold-certified and is an Environmental Protection Agency Energy Star building, and PPPL was one of just three facilities in the country to receive the DOE's gold-level GreenBuy Award for its green buying program.

Some of PPPL's green initiatives and programs include: placing composting and recycling bins in the cafeteria and throughout the laboratory to allow PPPL to divert nearly 70 percent of its waste from landfills; reducing paper use by 30 percent over the past two years; using biodiesel in many of its vehicles, including its fire engine, ambulance and other emergency vehicles; and reducing energy use in non-experimental areas by more than 50 percent through upgrades to plant boilers, high-efficiency LED lighting and building improvements.